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    <h1>猫猫计算器</h1>
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        <div id="operation">
            <button id="seven">7</button>
            <button id="eight">8</button>
            <button id="nine">9</button>
            <button id="divide">/</button>
            <br />
            <button id="four">4</button>
            <button id="five">5</button>
            <button id="six">6</button>
            <button id="multiply">*</button>
            <br />
            <button id="one">1</button>
            <button id="two">2</button>
            <button id="three">3</button>
            <button id="sub">-</button>
            <br />
            <button id="zero">0</button>
            <button id="point">.</button>
            <button id="delete">&larr;</button>
            <button id="add">+</button>
            <br />
            <button id="left-bracket">(</button>
            <button id="right-bracket">)</button>
            <button id="clear">CE</button>
            <button id="equal">=</button>
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    <img id="cat" src="https://i0.hdslb.com/bfs/album/1c94f7bbd05bdf6122411af829e423e9aefbb52a.png@518w_1e_1c.png"
        alt="cat">

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